To evaluate the usefulness of ultrasonography, endoscopic retrieval, and the outcome of patients with diabetes mellitus presenting with ureteric obstruction caused by necrosed renal papillae. Material And Methods: Eleven seriously ill patients with diabetes mellitus, admitted into medical wards, were found to have ureteric obstruction complicated by urinary infection. The diagnosis was made by ultrasonography alone. Prompt relief followed endoscopic extraction of the offending necrosed papillae. Results: Ten patients improved dramatically. One patient died from septicemia. Conclusions: Ultrasonography appears to be a useful diagnostic method to diagnose ureteric obstruction. It is cheap, fast, and extremely reliable. Endoscopic extraction of the obstructing papilla offers the best chance for successful outcome.

Renal papillary necrosis (RPN) is commonly associated with diabetes mellitus. The sequestrated papilla may cause ureteric obstruction and may complicate further. Awareness, prompt diagnosis, imaging, and extraction of the obstructing papilla are essential for successful outcome.

Material and Methods

We report 11 cases of diabetes mellitus and obstructive RPN who presented to us in the last 12 months. All of them were febrile and seriously ill. Patients presented with loin pain, fever, chills, and disorientation and were admitted initially intothe medical wards.

Urological consultation was sought when medical treatment (antibiotics, diabetic control) failed to improve the condition, and the symptoms of ureteric obstruction persisted. Ultrasound was used as the single mode of diagnostic investigation.

Patients had papillae blocking either the lower or the entire ureter, PUJ, or bilateral pelvicalyceal system. Papillae were clearly identified on ultrasound scan, and, as shown in the film, the exact size of the obstructing papilla and the calcareous deposits over it was also seen. The obstruction resulted in infected hydronephrosis, pyonephrosis, and sepsis. In one patient, spiral CT scan showed emphysematous pyelitis but did not demonstrate the papilla.

Surgical intervention was made by cystoscopy, extraction of the protruding UV junction papilla, and DJ stenting. Ureteroscopy was done in 9 out of 11 patients to clear obstruction above the UVJ. In all cases, the obstructing renal papillae along with infected material were extracted. Eight were stented. All received antibiotics for 24 to 36 hours. One patient died soon after the procedure, as she developed hypotension possibly due to septicaemia, leading to cardiac arrest despite all resuscitative measures. Nine patients dramatically improved and were discharged after full recovery.

One patient had an additional obstruction in the left mid ureterthat could not be removed. A nephrostomy was done after 4 days of the initial extraction and maintained for 1 month. A nephrostogram at 1 month showed a patent ureter, and the nephrostomy tube was removed.

One patient, serial no.10 in the table, had multiple bilateral obstructing papillae and presented with anuria.

She was dialyzed, and bilateral RGP and stenting was done. One month later, she came back with blocked stents, and right ureteroscopy and basketting of multiple papillae was done. The left ureter could not be entered because of technical difficulties. She continues to be in a difficult condition and will undergo an open extraction if her general condition permits.

Results

Successful extraction of the papillae by cystoscopy and/or ureteroscopy with or without stenting has resulted in dramatic recovery of these seriously ill patients. Antibiotic coverage for 24-36 hours and optimizing the general condition, blood volume, and electrolytes has contributed to the good results.

Discussion

Among the causes of ureteral obstruction, renal papillary necrosis is a leading one among diabetics[1] . First described by Friedrich in 1877, over the years several reports have appeared. The autopsy report of the musical genius Beethoven in 1827 was the first classical description of analgesic RPN.

The causes of RPN symbolized by the mnemonic 'POSTCARDS' are pyelonephritis, obstruction, sickle cell disease, tuberculosis, cirrhosis, analgesics, renal trauma, diabetes, and systemic vasculitis. RPN is a sequel of compromise of the already poor blood supply from the vasa recta of the renal medulla and pyramids by attenuation or compression. RPN is a bilateral process with unilateral or bilateral presentation. Over 60% of cases present with positive urine culture. The necrotic papillae act as nidus for infection and stone formation[2] . They respond poorly to antibiotic treatment and may proceed to chronic pyelonephritis. The sequestrated papilla is the result of ischemia occurring in renal papillae and medulla. It may be present in a single kidney initially, but often the contralateral kidney will develop the problem within 4 years. It is rare in younger age group but presents in middle age, and diabetics form the majority. Analgesic nephropathy is an associated condition and causal factor of RPN[3],[4],[5],[6]

The past has seen the usage of IVU[7] , retrograde ureterography, and CT [8] to demonstrate obstruction and its site. These were all suggestive but never considered diagnostic, as the necrotic papilla could not be imaged either by X- ray, US scan, or CT scan. However, improved resolution of USS has been diagnostic in our study, and the obstructing papilla was imaged adequately.

Various surgical methods to relieve obstruction have been employed over the years. These include open nephrostomy, antegrade ureteroscopy with the help of flexible choledochoscope, PCN and antegrade approach, and passage and positioning of large ureteric catheter via cystoscope. Extreme cases required nephrectomy when there was gross pyonephrosis.

Rigid ureteroscopy arrived on the scene in 1987, and reports of relief following extraction of necrotic papillae have been sporadic.[9],[10],[11],[12] As recently as 2003, Japan reported the first successful endoscopic extraction.[13]

In the 11 cases reported here, none were taken up as emergency procedure. Instead, antibiotic coverage was provided for 24-36 hours before intervention. The use of antibiotics and hemodynamic stability achieved in this period attributed to the good results.

Conclusions

Ultrasonography alone appears to be a useful diagnostic modality. We advocate endoscopic extraction of the obstructing papilla as the preferred treatment modality in patients with diabetes mellitus.